'''Program Architecture''' is about the planning and design of a program. ** See Also ** [A simple mechanical system]: [API]: The mechanism by which other systems or components may interact with the system. [Concepts of Architectural Design for Tcl Applications]: [Design patterns in Tcl]: [Intelligent Design]: [Law of Demeter] : ''only talk to your immediate friends'' [Model / View / Controller]: [streams]: A fundamental building block. <> Learn to Program